// 跳转主页面
function LoginUrl() {
    if ($('#username').val() != "" || $('#password').val() != null) {
        if ($('#username').val() == "admin" && $('#password').val() == "admin123") {
            window.location.href = "./demo.html";
        }
    }
};
//清空
function Empty() {
    $('#username').val("");
    $('#password').val("");

}